Direct measurements of intracellular pH, and other intracellular ions/substrates, will be made to establish the relationships between these cellular functions and membrane/contractile responses. Tissues will be exposed to conditions that challenge their activity and changes noted. Remedial measures will be initiated in an effort to counteract the lesion(s) produced by the tissue challenge. It is anticipated that there will be a high degree of correlations between changes in intracellular milieu, as indicated by pH, pO2, pIONS, and tissue function. These data would then serve as the basis for both further research to define the relationships between changes in cell function and cellular living milieu, and also provide for rational therapeutic measures for conditions produced in the laboratory and found elsewhere.